1 files changed, 131 insertions, 0 deletions
diff --git a/spec/ruby/core/module/remove_method_spec.rb b/spec/ruby/core/module/remove_method_spec.rb
new file mode 100644
index 0000000000..94b255df62
--- /dev/null
+++ b/spec/ruby/core/module/remove_method_spec.rb
@@ -0,0 +1,131 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+module ModuleSpecs
+  class Parent
+    def method_to_remove; 1; end
+  end
+
+  class First
+    def method_to_remove; 1; end
+  end
+
+  class Second < First
+    def method_to_remove; 2; end
+  end
+end
+
+describe "Module#remove_method" do
+  before :each do
+    @module = Module.new { def method_to_remove; end }
+  end
+
+  it "is a public method" do
+    Module.should have_public_instance_method(:remove_method, false)
+  end
+
+  it "removes the method from a class" do
+    klass = Class.new do
+      def method_to_remove; 1; end
+    end
+    x = klass.new
+    klass.send(:remove_method, :method_to_remove)
+    x.respond_to?(:method_to_remove).should == false
+  end
+
+  it "removes method from subclass, but not parent" do
+    child = Class.new(ModuleSpecs::Parent) do
+      def method_to_remove; 2; end
+      remove_method :method_to_remove
+    end
+    x = child.new
+    x.respond_to?(:method_to_remove).should == true
+    x.method_to_remove.should == 1
+  end
+
+  it "updates the method implementation" do
+    m_module = Module.new do
+      def foo
+        'm'
+      end
+    end
+
+    a_class = Class.new do
+      include m_module
+
+      def foo
+        'a'
+      end
+    end
+
+    a = a_class.new
+    foo = -> { a.foo }
+    foo.call.should == 'a'
+    a_class.remove_method(:foo)
+    foo.call.should == 'm'
+  end
+
+  it "removes multiple methods with 1 call" do
+    klass = Class.new do
+      def method_to_remove_1; 1; end
+      def method_to_remove_2; 2; end
+      remove_method :method_to_remove_1, :method_to_remove_2
+    end
+    x = klass.new
+    x.respond_to?(:method_to_remove_1).should == false
+    x.respond_to?(:method_to_remove_2).should == false
+  end
+
+  it "accepts multiple arguments" do
+    Module.instance_method(:remove_method).arity.should < 0
+  end
+
+  it "does not remove any instance methods when argument not given" do
+    before = @module.instance_methods(true) + @module.private_instance_methods(true)
+    @module.send :remove_method
+    after = @module.instance_methods(true) + @module.private_instance_methods(true)
+    before.sort.should == after.sort
+  end
+
+  it "returns self" do
+    @module.send(:remove_method, :method_to_remove).should equal(@module)
+  end
+
+  it "raises a NameError when attempting to remove method further up the inheritance tree" do
+    Class.new(ModuleSpecs::Second) do
+      -> {
+        remove_method :method_to_remove
+      }.should raise_error(NameError)
+    end
+  end
+
+  it "raises a NameError when attempting to remove a missing method" do
+    Class.new(ModuleSpecs::Second) do
+      -> {
+        remove_method :blah
+      }.should raise_error(NameError)
+    end
+  end
+
+  describe "on frozen instance" do
+    before :each do
+      @frozen = @module.dup.freeze
+    end
+
+    it "raises a FrozenError when passed a name" do
+      -> { @frozen.send :remove_method, :method_to_remove }.should raise_error(FrozenError)
+    end
+
+    it "raises a FrozenError when passed a missing name" do
+      -> { @frozen.send :remove_method, :not_exist }.should raise_error(FrozenError)
+    end
+
+    it "raises a TypeError when passed a not name" do
+      -> { @frozen.send :remove_method, Object.new }.should raise_error(TypeError)
+    end
+
+    it "does not raise exceptions when no arguments given" do
+      @frozen.send(:remove_method).should equal(@frozen)
+    end
+  end
+end